1. Field of the Invention
The invention relates in general to a switch circuit, a pixel element and a display panel using the same, more particularly to a switch circuit, a pixel element and a display panel using the same.
2. Description of the Related Art
In order to enhance the value of display devices such as a liquid crystal display (LCD), a technology of memory in pixel (MIP) has been introduced into various fields of application. MIP can be used to for example reduce power consumption of different display devices, such as a reflective or a transflective LCD.
There are different types of MIP. In order to achieve same bit number, a dynamic random-access memory (DRAM) type of MIP requires less circuit elements, as compared with that of a static random-access memory (SRAM) type of MIP. In other words, the DRAM type of MIP, such as a self-refreshing in pixel type MIP (SRP-MIP), has a reduced circuit complexity, and a higher transmissive aperture ratio than that of SRAM type of MIP. In view of this, the DRAM-based MIP is suitable for display devices which require high aperture ratio, or high resolution such as pixels per inch (PPI).
In most MIPs, a memory is used to maintain the gray level of the MIP without new data being provided from a source driver, so that power consumption can be reduced. The memory is for example such as a capacitor which is used for storing the state of an image data storage capacitor which stores with an image data. After the state of the image data storage capacitor is memorized in the memory, the image data storage capacitor can have its image data refreshed or maintained according to the memorized state.
In MIP, however, the layout area of its memory reduces the transparent or transmissive area in the whole pixel area. This affects the aperture ratio, as well as the resolution of display devices. Due to inverse relationship between the aperture ratio and the resolution, in a case where a display device requires a high resolution, the aperture ratio will become unacceptably small.